<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>if分支语句测试</title>
		<script type="text/javascript">
			var score = prompt("请输入您的成绩：");
			console.log(score);
			if (score >= 80 && score <= 100) {
				document.write("您的成绩为：优秀！");
			} else if (score >=60 && score < 80) {
				document.write("您的成绩为：中等！");
			} else if (score >= 0 && score < 60) {
				document.write("您的成绩为：不及格！");
			} else {
				document.write("输入错误！请输入0到100的整数");
			}
		</script>
	</head>
	<body>
	</body>
</html>
